I saw this muffler on a 01+ civic today. it was a chambered muffler with two tips, but one was like stock size and the other was like 3.5". does anyone know what this is and what its claimed benefits are? i dont know where else to ask this question.. im trying to find a picture but i dont know how to search for it.

 

Greddy Dynamic Tune muffler. They discontinued them.

From Greddy's web site:
Designed as an economical and versatile alternative to our famous Cat-back exhaust line, the new Dynamic Tune Muffler (DT-Muffler) series brings new options to performance Axle-back exhaust systems. This full stainless steel one piece system bolts onto OEM or factory position piping and then divides into dual inlets on our straight-through muffler. Exiting the oval muffler are our unique two angled round tips, measuring 80 and 42mm. The smaller tip can be capped to allow for sound and flow adjustments. This can change the tone and drivablity throughout the operating range.

 

interesting. thanks for the response!